Polishing apparatus



Aug. 6, 1963 F. T. BILLS POLISHING APPARATUS 3 Sheets-Sheet 1 Filed Feb. 12, 1962 Aug. 6, 1963 F. T. BILLS PoLIsHING APPARATUS Filed Feb. l2, 1962 3 Sheets-Sheet 2 Aug. 6, 1963 F. T. BILLS 3,099,853

PoLIsHING APPARATUS Filed Feb. 12, 1962 :s sheets-sheet s United States Patent O 3,099,353 PQLLSHNG APPARATUS Floyd 'I'. Bills, Vandergritt, Fa., assigner to Allegheny Ludlum Steel Corporation, Brackenridge, Pa., a corporation of Pennsylvania Filled Feb. 12, 1962, Ser. No. 172,625 9 Claims. (Si. 1S-97) This invention relates to an apparatus for polishing cylindrical objects, and in particular to polishing rolls for use in rolling mills.

Heretofore there has been many devices used for polishing cylindrical objects, especially rolling mill rolls, which predominantly depended upon the speed of rotation of the roll for the efliciency of the device. With the size of the rolling mill rolls becoming in some instances quite large, the equipment necessary to rotate these rolls at high speeds became rather large and costly. Other devices which have been used predominantly make use of a point contact for polishing, and as a result thereof the eiciency of this system is exceedingly low. The apparatus of the present invention is suitable for polishing cylindrical objects, is adaptable for use with existing equipment, and utilizes double action for great eiciency.

An object of the present invention is to provide an apparatus suitable for use in the polishing of cylindrical objects.

Another object of this invention is to provide an apparatus for use in polishing cylindrical objects in which a large area is polished with a simultaneous application of a reciprocal and rotary motion.

A more specific object of this invention is to provide an apparatus which may be used in conjunction with present existing machinery for the polishing of rolling mill rolls to provide an extremely highly polished surface thereon.

These and other objects of the present invention will become apparent when taken in conjunction with the description and the drawings in which:

FIGURE 1 is a schematic view of the general arrangement of the apparatus of the present invention;

FIG. 2 is a partial vertical view, partly in section, of the reciprocating mechanism looking into the polishing face of the apparatus;

FIG. 3 is a partial plan view of the polishing apparatus with the polishing face at the lower edge thereof;

FIG. 4 is a partial end View of the polishing apparatus with the polishing face at the upper edge thereof;

FIG. 5 is a partial view in section taken along the line A-A of FIG. 2;

FIG. 6 is a partial view in section taken along the line B-B of FIG. 2, and

FIG. 7 is a view in partial section taken along the line C-C of FIG. 2.

Referring now to the drawings, and to FIG. 1 in particular, this invention is illustrated by reference to the polishing apparatus shown generally -at 19 which is utilized in polishing a cylindrical metallic object 12, for example, a roll for use in a rolling mill. The polishing apparatus is formed of a support 14 on which a cradle, shown generally at 16, is mounted for longitudinal movement along the support 14. The cradle 16 comprises an upwardly extending chuck housing 17 and a chuck 18 forming one end of the cradle 16 and an upwardly extending tail stock housing 19 having a tail stock 29 disposed therein, forming the other end of the cradle 16. The chuck 1S and tail stock 20 are aligned to have a longitudinal axis pass through the centers of said chuck 1S and tail stock 2li. The cylindrical object 12 is thus supported in the chuck 18 between the tail stock 29 and is aligned therein for rotatable movement about said longitudinal axis passing through said chuck 18 and tail stock 2i). A power means (not illustrated) is disposed for imparting a rotary movement to the chuck 18 and to the object 12 supported in the cradle.

The support 14 also carries a spindle housing 22 mounted thereon which is disposed for lateral movement in relation to the cradle 16. The spindle housing 22 carries a shaft 24, one end of which is `disposed to extend a predetermined distance beyond the housing 22. The other end of said shaft 24 is connected to a drive spindle mechanism shown generally at 26 which is connected to the shaft of a suitable drive motor 2S carried on the housing 22 whereby a rotary motion may be imparted to the drive spindle 26 for driving the shaft 24.

1Referring now more particularly to FIGS. 2, 3, 4, 5 and 6, the polishing mechanism is shown generally at 36 and comprises, inter alia, a base 32 rigidly secured to the spindle housing 22 by means of bolts 34, as more clearly illustrated in FIGS. 3 1and 4, and a mounting plate 38 which is disposed for seating engagement within the base 32 as will be more fully described. Preferably, the base 32 is provided with a slot 36 which is preferably of a dovetail arrangement and is secured in a plane which is preferably perpendicular to the direction of longitudinal movement of the carriage 16. The mounting plate 38 is provided with a complementary dovetail portion 4i) which matches the slot portion 36 of the base 32 and which, when iitted into the portion 36, will securely anchor the polishing mechanism Sti' to the spindle housing 22. A guide bar 42 (see FIG. 5) is disposed to be secured to the mounting plate 68 by means of bolts 44 which are preferably recessed within the dovetail section 40k of the mounting plate 38, as illustrated in FIGS. 5 and 6. The guide bar 42 comprises a channel portion 46 which is disposed along the length of one side thereof and a tongue portion 48 which is disposed to extend outwardly from and along the length of the other side of the guide bar 42 and is aligned perpendicularly to the slot portion 36 of the base 32.

A reciprocating head, shown generally at 50, is disposed in spaced relation over the guide bar 42. The reciprocating head 50 (see FIG. 5) comprises a carrier plate 52 which is disposed in spaced relation over the guide bar 42, a substantially T-shaped bearing bar S4 secured to said carrier plate 52 by means of bolts 56 and which is disposed for sliding engagement along the channel portion 46 of the guide bar 42, and a bearing channel 58 disposed to be secured to the carrier plate 52 by means o-f bolts 60, and which is also disposed for sliding engagement with the tongue portion 48 of the guide bar 42. The bearing channel 58 which is secured to the carrier plate '52 is laterally adjustable with respect to the tongue portion 48 of the guide bar 42 by changing the position of the bolts 60 in the slotted opening 62 which extends through the carrier plate 52. Thus the relative sliding engagement between the substantially T-shaped bearing bar 54 and the channel portion 46 of the guide bar 42 may be adjusted by repositioning the bearing channel 5S so as to provide the proper sliding engagement of the reciprocating head over the guide bar 42. The reciprocating head 50 is also provided with a pair of side connecting bars 64 and 66 which are positioned along the length of the carrier plate 52 near the opposite outer extremities thereof adjacent the T-shaped bearing bar 54 and the bearing channel 58, respectively, and said connecting bars are disposed to extend a predetermined distance beyond the end of the carrier plate 52, each terminating in threaded portion 7G. The connecting bar 64 is secured adjacent the substantially T-shaped bearing bar 54 by means of bolts 68 and the companion connecting bar 66 is secured to the carrier plate 52 by means of bolts 72 adjacent the bearing channel 58. Set screws 74 extend through connecting bar 66 into contact with the bearing channel 58- and are secured in position by locking -nuts 76 to thereby aid in maintaining the bearing channel 58 in its proper sliding relation with the tongue portion 48 of the guide bar 42. As thus assembled, the reciprocating head 50 may be moved longitudinally along the guide bar 42. A pair of end plates 78 (see FIGS. 3 and 6) is disposed to be secured to the carrier plate 52 by means of screws S0. The end plates 78 are provided with a slotted portion 82, the function of which will be referred to hereinafter.

A pivot plate 84 (FIGS. 3, 5 and 6) is disposed to be secured in spaced relation over the carrier plate 52 and is pivotally mounted to the end plates 78 in said spaced relation by means of pivot bolts 86 which are disposed to extend through the slotted portion 82 of the end plates 78. A plurality of springs 88 are disposed over the heads of the bolts 68 and 72 between the carrier plate 52 and the pivot plate 84 to maintain a spring-biased relation between the pivot plate 84 and the carrier platep52. A stop plate 90 is disposed intermediate each of the end plates 78 and the pivot plate 84 and extends across the slotted openings 82 of the end plates 78. The stop plate 90 is secured to the end plate 78 by means of screws 92 and extends upwardly with its upper edge terminating closely adjacent the upper edge of the end plate 78. The stop plate 90 is also provided with a U-shaped slot which coincides with the slotted portion 82 of the end plate 7 8 when kthe stop plate 90 is secured in position with screws 92 to thereby permit only limited movement of the bolt 86 in the slotted opening `82. The pivot plate 84 is also provided with a pair of outwardly extending lugs 94 disposed on opposite sides thereof, each of which has an opening formed therein, to be referred to more fully hereinafter. The outwardly extending lugs 94 of the pivot plate 84 are disposed in a plane perpendicular -to the plane of the movement of the reciprocating head 50. A pad-retaining plate 96 is disposed to be secured in spaced relation between said outwardly extending lugs 94 of the pivot plate 84 and is pivotally secured to the pivot plate 84 by means of pivot screws 98 which extend through the openings of the lugs 94, locking nuts 100 being provided to hold the screws 98 in position. The pad-retaining plate 96 may be provided with a plurality of spaced openings 102 which are disposed to receive screws or the like (not shown) which aid in securing a polishing pad '4 (FIG. 4) within the confines of the pad-retaining plate 96.

Referring now to FIGS. 2 and 3, reference is particularly directed to the connecting bars 64 and 66, each having a threaded portion 70 which extends beyond the connes of the carrier plate 52.

A pair rof bearing housings 106 and 108 having suitable openings therein are positioned in spaced relation on and disposed to extend across the threaded portions 70 of connecting bars 64 and 66, and each of said bearing housings is secured thereto by means of lock nuts 110 disposed on opposite sides of the housings and in engagement with the threaded portions 70 of bars `64 and 66. Each of the bearing housings 106 and 108 is provided with a recess intermediate its ends and positioned in alignment with one another in the opposing faces and in which a bearing 112 is disposed to be secured. The bearing is held for rotating movement about an axis which is perpendicular to the direction of movement of the reciprocating head. Each bearing 112 is preferably secured within its respective bearing housing by means of a bolt 114 which is disposed to extend through inner race 116 of the bearing in coincidence with the axis about which the bearing rotates. A cover plate 118 is secured to the bearing housing by means of screws 120 to facilitate easy inspection and removal of the bearings.

Referring now to FIG. l, a wobble wheel 122 is disposed to be carried adjacent the free end of the shaft 24, said wobble wheel having an inclined hub 124 so as to provide the periphery of said wobble wheel 122 with rotation through a predetermined amplitude upon the rotation of said wobble wheel 122 by means of shaft 24, spindle drive 26 and motor 2S. The wobble wheel 122 is disposed to extend a sufficient distance so that the periphery thereof is in contact with the outer bearing race 126 of the spaced bearings 112. As thus assembled, the rotary motion of the wobble wheel 122 will provide a reciprocating motion at the periphery thereof which is in contact with the freely rotating outer bearing race 126, thus converting the rotary movement of the wobble wheel 122 into reciprocating motion of a predetermined amplitude which is transmitted through the reciprocating head 56 to the polishing pad 104.

In operation, a cylindrical object, for example a rolling mill roll 12, is positioned in the cradle 16 intermediate the chuck housing 17 and tail stock housing 19. The chuck 18 is secured into operative engagement with one end of the roll 12, while the other end of roll 12 is supported for rotating movement by means of tail stock 20. The wobble wheel 122 is next secured to the shaft 24, following which the base 32 is bolted to the spindle housing 22 by means of bolts 34. Thereafter, the polishing apparatus is set into position within the base by means of the mounting plate 38 with its dovetailed protrusion 40 being set in operative engagement within the slotted portion 36 of the base 32. Simultaneously with the positioning of the polishing apparatus through matching the dovetailed portion 40 of the mounting plate *38 in slot 36 of the base 32, the reciprocating head 50 is moved into an aligned relationship so that the periphery of the wobble wheel 122 is disposed in engagement with the outer bearing race 126 contained within the bearing housings 106 and 108. As thus secured into position, the polishing pad 104 is placed within the pad-retaining plate 96 by means of fasteners (not shown) extending through the openings 102 of the pad-retaining plate 104 and the spindle housing 22 with its associated apparatus is moved laterally on support 14 so that the polishing pad 104 is placed in contact with the surface to be polished of the roll 12. Where desired, a suitable abrasive may be applied to the pad 104 or it may be continuously fed to the pad 104 through some external means (not shown), such abrasive material comprising, for example, an oil suspension of diamond dust having a predetermined fineness.

Power i-s supplied fto ythe chuck 18 for rotating the roll 12 about the longitudinal axis through the chuck 18 and tail stock 20. Motor 28 is engaged which supplies rotary movement to the drive spindle mechanism 26 which turns the shaft 24, thus imparting `a rotary mot-ion to the wobble wheel 122 secured to the end thereof. Since the wobble wheel 122 is provided with an inclined hub 124, the rotation of wobble wheel 122 provides a reciprocating motion fof predetermined amplitude `to the periphery of said wobble wheel 122 and since lthe wobble wheel 122 is disposed in seating engagement between the spaced bearing houslngs 106 and 108 and in rolling contact with the outer bearing race 126 of each of the bearings 112, the reciprocating movement of predetermined amplitude is transmitted from the periphery of the wobble wheel lto the bearing race.

Since the outer bearing race is secured in rolling contact to'the inner race 116 of each of the bearings 112 which 1n turn are secured by means of bolts 114 to the bearing housings 106 and 108, the reciprocating movement 1s thus transmitted to the bearing housings 106 and 108. The bearing housings 106 land 108 thus transfer reciprocating motion through the stop nuts secured on the threaded portions 70 of the connecting bars 64 and 66 to the carrier plate 52 of the reciprocating head 50. T his reciprocating motion which is transferred .to the carrler plate 52 through the bolts 72 which secure the connecting arms 64 and 6610 the carrier plate 52 of the reciprocating head 50 is transmitted to the end plates 78 secured to the carrier plate 52 by means of screws 80 and this same motion is imparted to the pivot plate 84 which is carried by the end plates 78. In turn, this same movement is transferred to the outwardly extending lugs 94 of the pivot plate S4 to lthe pad-retaining plate 96 and thus ultimately to the pad 104 secured within the pad-retaining plate 96.

Since the reciprocating head 5t? is provided with a bearing channel SS and `a substantially T-shaped bearing bar 54 which are disposed in slidable engagement with the tongue portion 4S and with the channel portion 46, respectively, of the guide bar 42, the reciprocating head is thus moved in a predetermined plane through a predeterruined amplitude. By the proper adjustment of the channel bearing bar 51S by means of the set screw 74 extending through the connecting mm 66, the relative positioning of the reciprocating head Sii in spaced relation over the guide bar 52 is accomplished by thus adjusting the set screws 74 and locking the same in position with lock nuts 7 6. As thus locked in position, the bolt ed which extends through the slotted portion 62 of the carrier plate 52. is thus secured into position for the operative engagement of the reciprocating head Sil in spaced relation over the guide bar 4 secured to the mounting plate 3S.

In order to compensate for any yalignment diihculties with the pad-retaining plate and kto insure the proper pressure of the polishing pad in engagement with the surface to be polished of the roll l2, the pivot plate S4 is maintained in spring biased relation by means of springs 8S with respect to the carrier plate S2 `and is thus free to rotate about screw S6 which pivotally secures the pivot plate S4 to the end plates 78. This will also provide for any torque compensation incurred by reason of the movement of the roll 12 which is rotatably supported in the carriage 16. In the same manner, pad-retaining plate 9o is pivotally secured Within the lugs 94 of the pivot plate 84- to thus permit a double pivot land `alignment: of the polishing pad to the contour and crown of the cylindrical article thus being polished.

By thus providing for the ylimited pivotal movement of the pad-retaining plate and the pivot plate las Well as the spring biased relation of maintaining the pivot plate in spaced relation to the carrier plate, the reciprocating motion as thus transmitted from the wobble wheel to the polishing pad permits the double polishing `action to be accomplished on the roll. Moreover, the spring biased relation between the pivot plate 84 `and the carrier plate 52 permits the application lof la predetermined vamount of pressure to be applied to the polishing pad 104 in contact with the surface of the roll 12. Since the pad-retaining plate is capable of utilizing a contour-shaped pad, a large `area may be buried, depending upon the amplitude of the reciprocating head `as determined by the rangle of inclination of the hub i24- of the wobble wheel 12,2, together with the rotary movement of the cylindrical :object 12. The apparatus thus described is highly eicient in providing a high luster ora highly polished surface to cylindrical objects.

I claim:

1. In a polishing apparatus, lthe combination comprising, a base, ia mounting plate removably secured to said base, a guide bar secured to said lmounting plate and having a longitudinal channel portion extending along the length of one side thereof and a tongue portion extending along the length of the opposite side, a reciprocating head disposed in spaced relation over said mounting plate, a substantially T-shaped bearing bar secured to said reciprocating head and a substantially U-shaped bearing chiannel also secured to said reciprocating head, said T-shaped bearing bar .and U-shaped bearing channel being disposed in spaced relation to each other and in registry with said channel portion yand said tongue portion, respectively, of said guide bar for securing said reciprocating head in sliding engagement, a pivot plate pivotally mounted in spring biased spaced relation on said reciprocating head, la retaining plate pivotally secured in spaced relation `on said pivot plate, a polishing member removably secured in seating engagement on said retaining plate, and means connected to said reciprocating head for transforming rotary motion to reciprocating mot-ion to eiect a movement `of said reciprocating head through a predetermined amplitude in a predetermined plane.

2. ln `a polishing apparatus, the combination comprising, `a base, la mounting plate removably secured to said base, a guide bar secured to said mounting plate and having a longitudinal channel portion extending -along the length fof one side thereof `and `a tongue portion extending `along the length of the opposite side, a reciprocating head disposed in spaced relation over -said mounting plate, a substantially T-shfaped bearing bar secured to said reciprocating head and a substantially U-shaped bearing channel also secured to said reciprocating head, said T-shaped bearing bar and U-shaped bearing channel being disposed in spaced relation to each other and in registry with said channel portion and said tongue portion, respectively, of said guide bar for securing said reciprocating head in sliding engagement, a pair :of end plates secured to said reciprocating head, `a pivot plate carried by said `end plates in spring biased spaced relation to said reciprocating head, a retaining plate carried by said pivot plate in spaced relation thereto, `a polishing member removably secured in seating engagement on said retaining plate, `and means connected to said reciprocating head for transforming rotary motion to reciprocating motion to eect a movement of said reciprocating head through a predetermined amplitude in a predetermined plane.

3. In a polishing apparatus, lthe combination comprising, a base, a mounting plate removably secured to said base, a guide bar secured to said mounting plate and having a longitudinal channel portion extending along the length of one side thereof and a tongue portion extending outwardly from and along the length of the opposite side, a lreciprocating head disposed in spaced relation over said mounting plate, a substantially T-shaped bearing bar secured to said reciprocating head and a substantially U- shaped bearing channel yalso secured to said reciprocating head, said T-shaped bearing bar and U-shaped bearing channel being disposed in spaced relation to each other and in registery with said channel portion and said tongue portion, respectively, of said lguide bar for securing said reciprocating head in 4sliding engagement, a pair of spaced longitudinally extending connecting arms secured to said reciprocating head, a pair of end plates secured to said reciprocating head, a pivot plate carried by said end plates in spring biased relation to said reciprocating head, a retaining plate carried by said pivot plate in spaced relation thereto, a polishing member removably secured on said retaining plate, a pair of bearing housings disposed to extend yacross the connecting bars and secured in predetermined spaced relation to one another, and means disposed in operative engagement between said bearing housings for transforming rotary motion to reciprocating rnotion to effect movement of said reciprocating head through :a predetermined amplitude in la predetermined plane.

4. In a polishing apparatus, the combination comprising, a base, a mounting plate removably secured to said base, a guide bar secured to said mounting plate and having a longitudinal channel portion extending along the length of one side thereof and a tongue portion extending outwardly trom and along the 'length of the opposite side, Ia reciprocating head disposed in spaced relation over said mounting plate, a substantially T-shaped bearing bar secured to said reciprocating head and a substantially U-shaped bearing channel also secured to said reciprocating head, said T-shaped bearing bar and U-shaped bearing channel being disposed in spaced relation to each other and in registry with said channel portion `and said tongue portion, respectively, of said guide bar for securing said reciprocating head in sliding engagement, a pair of spaced longitudinally extending connecting arms secured to said reciprocating head, a pivot plate pivotally mounted in spring biased spaced relation on said reciprocating head, a pad-retaining plate carried by said pivot plate in spaced relation thereto, a polishing pad disposed in seating engagement within said pad-retaining pl-ate, a pair of bearing housings disposed to extend `across the connecting bars and secured thereto in predetermined spaced relation to one another, a Irotating drive means, and means connected ibetween said drive means and said bearing housings for converting the rotary motion of said drive means into reciprocating motion to effect a reciprocating movement of -said bearing housings and the reciprocating head connected thereto whereby the reciprocating head is moved through a predetermined amplitude in a predetermined plane.

5. In a polishing apparatus, the combination comprising, a base, 'a mounting plate removably ysecured to said base, a guide .bar secured to said mounting plate and having a longitudinal channel portion extending along the length of one side thereof and a tongue portion extending outwardly and along the length of the opposite side, a reciprocating head disposed in spaced relation over said mounting plate, a substantially T-shaped bearing bar secured to said Ireciprocating head and a substantially U-shaped bearing channel also secured to said reciprocating head, said T-shaped bearing bar and U-shaped bearing ch-annel being disposed in spaced relation to each other and in registry with said channel portion and said tongue portion, respectively, of said guide bar for securing said reciprocating head in sliding engagement, a pair of spaced longitudinally extending connecting bars secured to the reciprocating head, a pair of end plates secured to said reciprocating head, a pivot plate carried by said end plates in spring biased spaced relation to said reciprocating head, a pad-retaining plate carried by said pivot .plate in spaced relation the-reto, a polishing pad disposed in seating engagement Within said pad-retaining plate, a pair of bea-ring housings disposed to extend across said connecting bars and secured there to in predetermined yspaced relation to one another, a bearing secured in each bearing housing and disposed -fcr movement about an axis perpendicular to the plane of movement of said reciprocating head, a wobble wheel disposed for seating engagement between said bearings about the periphery of said wobble Wheel, and means lfor supplying rotary motion to said wobble wheel.

6. In a polishing apparatus, the combination comprising, ya base having a mounting slot contained therein, a mounting plate disposed for seating engagement within the mounting slot of the base, a guide bar secured to the mounting plate and having a channel disposed along the length of one lside o-f the guide bar and a -tongue portion protruding outwardly from and along the length of the other side of the guide bar, a reciprocating head disposed in spaced relation over the mounting plate, said reciprocating head being formed of a carrier plate disposed in spaced relation over the guide bar, a `substantially T- shaped bearing bar secured to the carrier plate and a substantially U-shaped bearing channel secured to the carrier plate, said T-shaped bearing bar cooperating with the channel of the guide bar in sliding engagement therewith ,and said U-shaped bearing channel cooperating with the tongue portion of the guide bar in sliding engagement therewith to support said carrier plate for reciprocating movement in spaced relation over the guide bar, a pair of end plates secured to the carrier pla-te in a plane substantially perpendicular to the direct-ion of movement of the carrier plate, said end plates each having a centrally located slot near the upper edge of the end pla-te, a pivot plate disposed to extend between said end plates in spaced relation to the carrier plate, means for pivotally securing said pivot plate to the end plates through the end plate "slots, said pivot plate also having a pair of upwardly extending lugs secured to the pivot plate in a plane perpendicular to the .plane of said end plates, a plurality of springs disposed in spaced relation to one another between the pivot plate and the carrier plate, a pad-retaining plate disposed in spaced relation to the pivot plate, said pad- S retaining plate being pivotally secured to the pivot plate through the upwardly `extending lugs of the pivot plate, and means disposed -to be secured to the carrier plate for imparting a reciprocating motion thereto.

7. yIn a polishing apparatus, the combination comprising, a b-ase having a mounting slot contained therein, a mounting plate disposed for seating engagement within the mounting slot of the base, a guide ibar `secured to the mounting plate and having a channel disposed along the length of one side of the guide bar and a tongue portion protruding outwardly `from and `along the length of the other side of the guide bar, -a reciprocating head .disposed in spaced relation over the mounting plate, said reciprocating head being `formed of a carrier plate disposed in spaced relation over the guide bar, a substantially T- yshaped bearing bar secured to the carrier plate and a substantially U-shaped bearing channel secured to the carrier plate, said T-shaped Kbearing bar cooperating with the channel of the guide bar in sliding engagement therewith and said U-shaped bearing channel cooperating with the tongue porton of the `guide bar in sliding engagement therewith to support said carrier plate for reciprocating movement in spaced rel-ation over the guide bar, a pair of spaced longitudinally extending connecting bars disposed to be secured to the carrier plate adjacent the bearing bar .and the bearing channel, each of said connecting bars lhaving one end thereof disposed to extend beyond said carrier plate and having a threaded portion thereon, a pair of end plates secured to the carrier plate in a plane substantially perpendicular to the direction of movement of the carrier plate, said end plates each having a centrally located slot near the upper edge of the end plate, a pivot plate disposed to extend between said end plates in spaced relation to the carrier plate, means for pivotally securing said pivot plate to the end plates 4through the end plate slots, said pivot plate also having a pair of upwardly extending lugs secured to the pivot plate in a plane perpendicular to the plane of said end plates, a plurality yof springs ldisposed in spaced relation to one another between the pivot plate and the carrier plate, a pad-retaining plate disposed in spaced rel-ation to the pivot plate, said pad-retaining plate being pivotally secured to the pivot plate through the upwardly extending lugs of the pivot plate, and means disposed to be secured to the connecting bars lfor imparting a reciprocating motion thereto.

8. In a polishing apparatus, the combination comprising, a base having a mounting slot contained therein, a mounting plate disposed for seating engagement within the mounting slot of the base, -a yguide bar secured to the mounting plate and having a channel disposed along the length of one side of the guide bar and a tongue portion protruding outwardly `from and along .the length of the other side of the guide bar, a reciprocating head disposed -in spaced relation lover the mounting plate, said reciprocating head being formed of a carrier plate disposed in spaced relation over the guide bar, a substantially T- shaped bearing bar secured yto the carrier plate and a substantially U-shaped bearing channel secured to the carrier plate, said T-shaped bearing bar cooperating with the channel of the guide bar in sliding engagement therewith and said U-shaped bearing channel cooperating with the rtongue portion of the guide bar in sliding engagement therewith to support said carrier plate for reciprocating movement in spaced relationl over the guide bar, `a pair of spaced longitudinally extending connecting bars disposed to be secured lto rthe `carrier plate adjacent the bearing lbar and the bearing channel, each of said connecting bars having one end thereof disposed to extend Ibeyond said carrier plates and having a threaded portion thereon, a pair of end plates secured to the carrier plate in a plane substantially perpendicular to the direction of movement of the carrier plate, said end plates each having a centrally located slot near the upper edge of the end plate, a pivot plate disposed to extend between said end plates in spaced relation to the carrier plate, means for pivotally securing said pivot plate to the end plates through :the end plate slots, said pivot plate also having a pair of upwardly extending lugs secured to the pivot plate in a plane perpendicular to the plane of said end plates, a plurality of springs disposed in spaced relation Ito one another between the pivot plate and the carrier plate, a pad-retaining plate disposed in spaced relation to the pivot plate, said pad-retaining plate :being pivotally secured to the pivot plate `through the upwardly extending lugs of the pivot plate, la pair of bearing housings disposed [to extend across the threaded portion of the connection bars and secured thereto in predetermined spaced relation to one another, and means `disposed in operative engagement between said tbearing housings for converting rotary motion into reciprocating motion whereby the reciprocating head is moved through a predetermined lamplitude in a predetermined plane.

9. In ra polishing apparatus, the combination comprising, a -base having a mounting slot contained therein, a mounting plate disposed for seating engagement the mounting `slot of the ibase, a guide bar secured to the mounting plate and having a rchannel disposed along the length of one `side of the guide -bar and -a `tongue portion protruding outwardly from and along the length of the other side of the guide har, a reciprocating head disposed in spaced relation :over Ithe mounting plate, `said reciprocating head being Vformed of a carrier plate disposed in spaced relation over the guide har, a substantially T- shaped bearing Ibar secured to the carrier plate yand a substantially U-shaped bearing channel secured :to the carrier plate, said T-shaped bearing har cooperating 'with the channel of the guide Ibar in sliding engagement therewith and said U-shaped hearing channel cooperating with the tongue portion of the guide har in sliding engagement therewith to supp-ort `said carrier plate for reciprocating movement in -spaced relation over the guide Ibar, a pair of spaced longitudinally extending connecting Abars disposed to he secured to the carrier plate -adjacent the hearing bar and the bearing channel, each of said connecting hars having one end thereof disposed to extend beyond said carrier plates and having a threaded portion thereon, a pair of end plates secured yto the carrier plate in -a plane substantially perpendicular to the direction of movement of the carrier plate, said end plates each having a centrally located slot near the upper edge of `the end plate, a pivot plate disposed .to extend between said end plates in spaced relation to .the carrier plate, means `for pivotally securing said pivot plate to the end plates through the lend plate slots, said pivot plate also having a pair of up- Wardly extending lugs secured to the pivot plate in a plane perpendicular cto the plane of said end plates, a plurality of springs disposed lin spaced relation to one another lbetween the pivot plate -and the carrier plate, a pad-retaining plate disposed in spaced relation to the pivot plate, said pad-retaining plate ibeing pivotally secured to the pivot plate through the upwardly extending lugs of the pivot plate, a pair of hearing housings disposed to eX- tend vacross the connecting bars yand secured |thereto in predetermined spaced relation to one another, =a hearing secured in each hearing housing and disposed -for movement about an axis perpendicular to the plane of movement of the reciprocating head, la wobble Wheel disposed 'for seating engagement between said ibearings about the periphery of said wobble wheel, and means for supplying rotary motion to the wobble fwheel.

References Cited in the le of this patent UNITED STATES PATENTS 1,037,852 Beam Sept. 10, A19'12 2,309,588 Hillix Jan. 26, 1943 FOREIGN PATENTS 537,633 Great Britain June 30, 1941 

1. IN A POLISHING APPARATUS, THE COMBINATION COMPRISING, A BASE, A MOUNTING PLATE REMOVABLY SECURED TO SAID BASE, A GUIDE BAR SECURED TO SAID MOUNTING PLATE AND HAVING A LONGITUDINAL CHANNEL PORTION EXTENDING ALONG THE LENGTH OF ONE SIDE THEREOF AND A TONGUE PORTION EXTENDING ALONG THE LENGTH OF THE OPPOSITE SIDE, A RECIPROCATING HEAD DISPOSED IN SPACED RELATION OVER SAID MOUNTING PLATE, A SUBSTANTIALLY T-SHAPED BEARING BAR SECURED TO SAID RECIPROCATING HEAD AND A SUBSTANTIALLY U-SHAPED BEARING CHANNEL ALSO SECURED TO SAID RECIPROCATING HEAD, SAID T-SHAPED BEARING BAR AND U-SHAPED BEARING CHANNEL BEING DISPOSED IN SPACED RELATION TO EACH OTHER AND IN REGISTRY WITH SAID 